Boundless Bio presents preclinical data on BBI-355

Boundless Bio presents preclinical and clinical pharmacodynamic data on its lead ecDNA-directed therapy, BBI-355, and research on ecDNA-mediated acquired resistance to chemotherapy at the American Association for Cancer Research Annual Meeting 2024. BBI-355 is a novel, oral, selective inhibitor of checkpoint kinase 1 being studied in the ongoing, first-in-human, Phase 1/2 POTENTIATE clinical trial in patients with oncogene amplified cancers. “Extrachromosomal DNA afford unique advantages to tumors, typically rendering existing therapies ineffective and correlating with poor patient outcomes,” said Chris Hassig, Ph.D., Chief Scientific Officer of Boundless Bio. “Our first poster presented this year at AACR demonstrated that BBI-355 overcame ecDNA-mediated targeted therapy resistance in preclinical tumor models by leveraging the enhanced reliance of ecDNA-driven tumor cells on CHK1 for survival. BBI-355 showed substantial antitumor activity, including complete and durable regressions, in preclinical oncogene amplified models.